Means for and method of preventing locomotive wheel slippage



' Sept. 28, 1 943. H, A. HOKE ETAL 2,330,712

MEANS FOR AND METHOD OF PREVENTING LOCOMOTIVE WHEEL SLIPPAGE Filed Feb. 11, 1943 2 Sheets-Sheet 1 INVENTORS:

2V0 a/z'E ell, BY

ATTORNEY MEANS FOR AND METHOD OF PREVENTING LOGOMOTIVE WHEEL SLIPPAGE Sept. 28, 1943. HQKE ETAL Filed Feb. 11, 1943 2 Sheets-Sheet 2 INVENTORS:

W M I mm M M Army s.

Patented Sept. 28, 1943 IATES OFFICE- MEANS EORAND METHODOF-PREVENTING.

LOGJQMOTIVEWHEELSLIBBAGE Harry A Hoke; Altoona, andNorman E2 Mei-roll,

Norwood, Pa assignors to" The Pennsylvania Railroad; Company; Philadelphia; Par; a: corporation of Pennsylvania AppiicationFebruary ll,1943, ,SerialNeg 475508 S GIaimSQ (01. 105-48) This invention relates to me ans.for preventing slippage of" locomotive. wheels, particularly in starting with. heavy loads,.,and,,also to methods of accomplishingthis result;

More specifically, the'present'inventionis concerned with steam locomotives. of .thetypehav ing four cylinders for motivating, the driving Wheels. i e

In theoperation oflocomotives of-the vkin l'referred'to; violent'slippageofone or the other set of the'driving; wheels often occurs by. reason. of their havinggat times, a, lesser coefllciency of friction. with. the. track rail'sthan the remaining set, so that'ordinarily allof 'thesteamlaheadnof the control throttle and'in theconnecting piping will pass to the cylinders-offsuch'slipping wheel sets. During disturbances of this sort, the enginemanhas no control whatever overthe supply of steam which. haspassed the control. throttle,

' and'as a: result, the locomotive will frequently come to a standstill befor the steam has passed out of the piping.

Our invention has for its chief. object to-overcome the difiiculties above pointed, out,,that is to say,.to make it possible-to slow down those drivers offthe setwhich may tend to slip without interfering, with the functioning of the other. set, until the Wheels of theslippinasettake hold. This objective is. attainedin practicev as hereinafter more fully disclosed. through provlsionjof automatic means. in the form of'a valve which is sensitive to differential steam flow in ,piDes-lead ing to the four cylinders pfthe. locomotivefor ca: n ity to-temnora i y. reduce thesupply of. steam to. the. motivating cylindersot the-slipping wheels,

' p r of cy inders.

Other objects andattendant advanta es of o v i n i l appear from the iollowing def tailed description of the attached drawings, whereof F 1 is a ro en o t fra mentary. view, more or. less. diagrammatic, partly side elevation and partly in longitudinalsectlon; ofia steam locomotive conveniently embodying; the present improvement. e

Fig; 2 is a cross sectionalview'of the locomo tive taken as indicated by the; angled arrows II-IIin Fig: l. s I v Fig. 3 is'a vie-w drawn toa-larger-scale and showing; partly inside elevation and-partlyinlorigitudinal section, the automatic valve means for preventing wheelslippage in accordance with our'invention:

Figs: 4 and 5 are-detailsectional views'taken -as respectively indicatedby the angledarrows I.V.- IV and V-V in Fig. 3. l

The locomotive. illustrated, in. Fig; l for the purposes of. exemplification herein isoflthe four cylinder typeand generallyof standard.construction having a boiler] and two pairs of cylinders 2 and .3 with. piston. rod and pitmanconnections ing sets of driving wheels [and 5.(in.1the usual way. At 6 is partially indicatedthe dry steam pipe which leads from the steamdoniefl of the boilerto' the header 8 of thesliperheater inthe smoke boat: at the front end ofjthe locomotive, withwhich header is incorporated a control throttle valve 1 0 of suitable. approved design. Extendingdownward from the housingof the throttlevalve lflat each side of theboiler is amanifold pipe. H, see Figs. 1 and 2, with axially? aligned horizontalflbranchpipes l2 and 13 leading in opposite directionstherefrom to the front andrear cylinders Zand13respe0tively. H i

{Ihe' wheel slippage prevention means with which ollrinvention is more especially concerned is ,indicated comprehensively. in the, drawings by the numeral, [5, and, as "shown, is in' the form of a valve with a body. I 6 of.,T configuration toiserve as aiuncture fitting between the manifold pipe ll and'its'horizontal'branches l2 and, [3. The axially aligned end portions l.1 and. l8 (Fig. 3) of the valve-body iii are. provided with .apertured flanges [9' and 2llf for connection'to similar op posingtflangeszl andQZZ at thecorresponding ends. of, the branch pipes l2 and I3 by means of' screw ,bolts and 24.1 The upward neck ofthe valve? body i6. is. likewise provided with an aperturedflange'ZS for connection to the shell of theboiler I and to a flange 2 at thelower end ofthemanifold pipe H byme'ans of screw bolts 28. Bearings 29 and 30 supported within the reduced'end portion'sl'l and resxiau within the Valve body "IE b'y radial spider Webs 3|- and-32, constitute-"guides for-the ends of slide-rod,

which is composed of two-"halves or sections 33 and 34: 7 As shown therodsections 33 and 34 are reversely threadedattheirihner ends and joined bya turn buckle 35; relative rotation of said sections being 'precluded by jam nuts 3(ii Mounted onthe rodsect'ions 33' and 34-"are discous closure members 31 and 38 respectively; which are adapted :to coact with ports 39 and 40 adjacent opposite ends of 'thevalvebody It in controlling flow to thecorresponding cylinders land 3 ajslpre ently" explained. .The closure members 31 and 33- are] cupped centrally as at 311;,"380 to' receive thecontiguous ends of coiled helical com pression springs 4i and 42 which respectively surround the rod sections 33 and 34 and which react upon flanged sleeves 43, 44 and 45, 46 free on said sections 33 and 34. As further shown, these sleeves 43, 44 and 45, .6 respectively abut the bearings 29 and 30, and the bottoms of the cup portions 31:; and 38a of the closure members 31 and'38 which latter are welded fast to the respective rod sections 33 and 34 against integral polygonal collars 4'! and 48 on said sections. The springs 45 and 42 are identical both as to size and power, and are regulatable through endwise 8dr,

justment of said rod sections 33 and 34 in relation to each other by means of the turn buckle 35. The turn buckle 35 is accessiblefor the'purpose of adjustment, through a hand hole -3 in .the valve body I6 near the bottom of the latter. This'hand hole 50 is normallyclosed by a remov able cover disc 5! having an axial stem 52 which passes outwardly through an apertured' clamp yoke 53 and is provided with a securing nut 54 at its protruding threaded end.

Preferably the body Iii of the valve I5 is formed from wrought parts which are integrally united by weld joints as conventionally indicated. How ever, it desired or foundmoreconvenient in prac tice, itmay be constructed as a casting.

The operation of ourinvention is as follows:

, Ordinarily, the slide rod with'its closure discs 3'! and 38 occupies the central neutral position in which it is shown in Fig. 3, with steam flowing uniformly through the branch pipes l2 and 13 to the cylinders} and '3. In the event that one set of driving wheels, for example the front set 4, should tend to slipdue to decreased friction with the track ,rails, there will be an accelerated flow of steam through the branch pipe I 2 whereby the slide rod will be drawn forwardly (rightduits directly responsive to differential velocity flow of steam in said conduits upon slippage of any of the driving wheels, to automatically reduce the supply of steam to the corresponding cylinders until such slipping wheels take hold.

3. In a steam locomotive, a boiler; a plurality of cylinders for. motivating separate driving wheels; a manifold with'branch conduits through which steam is conducted to the individual cylinders; and a control valve interposed at the juncture of the manifold and its branches, said valve having movable closure means directly responsive to difierential velocity flow of the steam in said branches upon slippage of any of the driving wheels, to reduce the supply of steam to the 'corresponding cylinders until such wheels take readily understood from Fig. 3. Siinilarlyfslippage of the rear set of driving wheels 5 will be attended by shifting of the rod to the leftand compression'of the spring 42, with resultant ap-.

proach of the'closure member 38. toward the port 4!) to reduce the supply of steam to the cylinder 3 until said wheels again take hold, .whereupon the parts will again be returnedto'neutral position by said spring 42. l I

Having thus described our invention, We clairnz.

1. In a steam-locomotive, a boiler; a plurality of cylinders for motivating separate driving wheels; conduits for conductingsteam from the boiler to the respective cylinders; and control means in said conduits directly responsive to differential velocity flow oisteam .in' said conduits upon slippage of any of the driving wheels, to automatically reduce the supply of steam to the corresponding cylinders until such. slipping wheels take'hold. a I

1. In a steam locomotive, aboiler; a plurality of cylinders for'winotivating. separate driving wheels;'conduits for conducting steam from the boiler to the respective cylinders; and a'control valve with movable closure means in said conhold. 1

4. The invention according to claim 3, wherein the branch pipes are aligned; and wherein the valve has a body in the form of a T fitting which connects the manifold pipe with the branch pipes, which has ports for communication 'into the branch pipes, and which houses closure means sensitive to differential flow of steam in said branch pipes to close the port for the cylinders of the slipping wheels.

5. The invention according to claim 3, wherein. the branch pipes are horizontally aligned; and wherein the valve has a body in the form of a T fitting which connects the manifold pipe with the branch pipes, which body has ports for communication into the branch'pipes, and which houses closure means sensitive to differential flow of steam in said branch pipes to close the port for the cylinders of the slipping wheels, said closure means including a slide rod guided at its ends in bearings coaxial with the aligned branch pipes, spacedclosure members on the intermediate portion of said rod adapted to coact respectively with the ports in said body, and yielding means to normally 'maintainthe rod and its closure members in neutral position within the valve body.

6. The invention according to claim 3, wherein the branch pipes .are aligned; and wherein the valve has a body in the form of a T fitting which connects the manifold pipe with the branch pipes, whichhas ports for communication into the branch pipes, and which houses closuremeans sensitive to differential flow of steam in the branch pipes to close the port for the cylindiets of the slipping wheels, said-closure means including a slide rod with its ends guided in bearings within the valve body axially of the aligned branch pipes, spaced-closure members on the intermediate portion of saidrod-adapted to coact respectively with the ports in said body, and balanced spring means in compression between the bearings and the respective closure members tending to normally maintain the rod and its closure members yieldingly in neutral position within the valve body.

7. The invention according to claim 3, wherein the branch pipes are aligned; and wherein the valve has a body in the form of a T fitting which connects the manifold pipe with the branch pipes, which has ports for communication into the branch pipes, and which houses closure means sensitive to differential flow of steam in the branch pipes to close the port for the cylinders of the slipping wheels, said closure means including a slide rod with separate end sections adjustably connected by a turn buckle and respectively guided in spaced bearings within the valve body axially of the aligned branch pipes, closure members on said rod sections adapted to coact respectively with the ports in said body, and spring means in compression between the bearing and body. 1

8. The method of operating a steam locomotive having plural cylinders for respectively imparting movement to individual sets of driving wheels, 10

which comprises supplying steam to all the cylinclers; and apportioning the steam directly in accordance with velocity differential in the flow of steam to the respectiv cylinders so that less steam is furnished to the cylinders of a slipping wheel than to the cylinders of the other wheels.

HARRY A. HOKE. NORMAN E. MERRELL. 

